Broaching machine



:Juny as, 1924. 3.5mm?

. A. DQNALDSON BROACHING MACHINE /m, ,7 11%? I' E amy i5 E924. 1,501,317

A, F. DONALDSQN BRUACHING MACHINE 4 Sheets-Sheet 2 Filed Feb; 13 1922 malga@ .Bully a5. 1924;

' A. F. DONALDSON BROAGHING MACHINE Filed Feb. 13, 1922 Patented July 15, 1924.

STATES l 1,501,317 PATENT Omen. i

AUeUsTUs r. DONALDSON, or TOLEDO, OHIO, AssIGNORTo THE :BUNTTNG BRAss a BRONZE COMPANY, or TOLEDO, OHIO, A CORPORATION or OHIO.

BROAC'HING MACHINE.

Appnaabnmea February 1s, 1922. sefialrnezrsaos;

To' all'y whom t concern: p

Be it known that I, AUGUSTUS` F. DON- ALDSON, a citizen of the United States, and a. resident ofToledo, in the county of Lucas and State of Ohio, have made an Invention Appertaining to a Broaching Machine; and I- do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled yin the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the charactersV of reference marked thereon, which forma part of this specification;

My invention has for its object to provide a'- broaching machine for efliciently broaching bushings. It particularly has for its object to provide a machine wherein sub-Y stantially perfect bushings may be rapidly breached. l

By my invention is provided a means for securely holding the bushings during? the'` breaching operation so that the cylindrical surfaces of the nished bushing will be'. substantially perfect in their concentricity notwithstanding the elasticity of the metal of which the bushing is formed. It also provides means for rapidly placing the bush-k ings in position for the broaching operationsv and delivering` the bushings from the machine. The invention provides other features and advantages that will appear from the following description and upon examination of the drawings.

The invention may be contained in structures of different forms. To illustrate a practical application of the invention I have selected a particular construction containing the invention as an example of such structures, and shall describeit hereinafter. The structure selected is illustrated in the accompanying drawings.

Figure l of the drawings is a side view of the machine shown partly in section. Fig.

` 2 is a sectional view of the broaching die.

operation .has been completed. Fig] is` a sectional view taken on theline 7'-`7` indicated in Fig. 6, and shows the'stripping means for strippingv the bushings' from? th'ef arbors of the machine'. Fig.I 8 illustrates tlieposition of the machine' and'fof the bush: ings upon the completion of the stripping operation. p n

The broaching operations are-performed in the well known punch press machine, it

being provided with a ram 1 that is driven?v by suitable gear wheels 2 in the 'manner'V well known in the art. y These parts are supported and guided in their` operationsby af suitable frame 3 which is alsOfprovided-wit'h a bolster plate Ll; The bolster plate 4' is rigidly secured to the frame by any suitable means Y i A pair of punches 5 are conne'ctedto the-v ram l so as to permit a' very slight lateral displacement of the upper ends of'- the punches, while the punches are held fromany endwise movement ordisplacementfre'la`` tive to the ram in order to neutralize? the effect of theV movements of a nonaligne'd* ram, so that the punches may be properly aligned by a centering means without plas!V ing the load caused by any inaccuracyof the rams path on the centering means, and also thereby avoiding any cramped con' dition of the centering means by reason' of the fact that a. plurality of punches may be used and centered by tlie centering means.

The punches are secured by sleeves 75, and rings 76. Balls 77 are located withinv the rings and the ends of the punches are held against the balls by the sleeves 75. VA very slight lateral and angular play in the ends of the punches is thus provided whereby the punches can adapt themselves to an aligning or centering means. The punches have` an end portion (Shaving diameters smaller than the body portions 7 of the punches. The 4ends of the punches, including the ends of the' body portions" 7,

' are located within a centering means even'f when the ram is raised tothe limit ofv i-tsf stroke. When the raml descends in its operation the punches pass through andV` are guided in their movement by the centering means.

The' means for centering the punches comprises a cross bar 8 having bored1 bossesV 9. The bosses are also provided with slot's l0 that form'ohannels on the inside ofl the' bosses. Guide blocks? .1.1 are# secured infthev g n Y '1,501,311v

channels 10 by means of plates 12 that are secured by screws, 13 that close the ends of the slots or channels. The blocks 11 are adjustably positioned within the bosses by means of the screws 14 which also operate to hold the blocks 11 in position. The blocks 11 are adjusted so as to hold the punches in position with reference to the other parts of the mechanism, as hereinafter described.

The crossbar 8 is secured to the bolster plate 4 by means of heavy blocks 15 and screws 16, and at a distance from the bolster plate that is slightly greater than the length ofthe bushings to be broached, whereby the centering means for the punches is brought very close to the work during the broaching operation.

A pair of dies comprising a cutting ring 21 and a compacting ring 22 is secured in the bolster plate 4. They are secured in position by means of sleeves 17, the bushings 18 located within the sleeves 17 and clamping rings 19 that are secured to the bolster plate by the clamps 20. The sleevrs 17 and the bushings 18 are provided with suitable shoulders that register with shoulders formed in the bolster plate and in the sleeves 17 to support the broaching die and to carry the end thrust or pressure that occurs during the broaching operations. The sleeves18, being ay perfect sliding fit on the arbors 25, serve also to guide the arbor while a bushing is passing through the dies, and firmly maintain the positions of the arbor concentric with the cutting and compacting dies.

rlhe cutting ring` 21 is located above the compacting ring 22 and has a substantially square cuttingedge 23. The inner surface of the compacting ring is cylindrical and is somewhat smaller than the inner diameter of the cutting ring. The upper inner edge 24 of the compacting ring 22 is rounded to cause the compression of small contiguous areas of the surface of the bushing, while the remainder of the. yinner surface of the ring 22 operates to burnish the surface of -its length, it is necessary toY support the bushing wall during the cutting and con pacting operation of the die concentric with the cutting and compacting edges of the dies and coaxial with the common axis of the said edges and the burnishing surface since bushings, particularly bronze bushings, are elastic, compressible and eXpansible, and consequently portions thereof will squeeze by al cutting edge without being Vsevered from the bushing, which results in enter recesses 26 that are formed in the ends of the punches 7. The bushings 27 are placed centrally over the dies and the ends of the arbors 25 enter the lower ends of the bushings and raise them into the bosses 9 and between the centering blocks 11. The

plunger 1 forces the punches 5 down and thus forces the bushings 27 over the arbors 25, and until the ends of the arbors enter the recesses 26 which they securely fit, whereupon the arbors, the punches, and the bushings move downward and the bushings are passed through the dies.

The arbors 25 are bolted to a movable head 28. The head 28 is guided in its movements by means of the bars 29. It is raised by means of the lever 30 that is fulcrumed on the frame 3. The lever 30 may be operated by means of the sector gears 31, one of which is connected to the lever 30, and the other to the lever 32. The lever 32 is also pivoted on the frame or on the bracketY 33 secured to the frame. The lever 32 is operated by a link 34 and a cam 35. The cam 35 is connected to the crank shaft that operates the ram 1. The cam 35 is provided with a surface 36 that operates upon a roller 37 connected to the rod 34 to depress the rod 34 and thus cause the lever 30 to raise the head 28, and consequently to raise the arbors 25, the head 28 being connected to the lever 32 by a pair of links 38. If desired, the cross head 28 may be held in its raised position by spring pressed latches 39 that engage the ends of the cross head 28. The latches 39 are pivoted to the frame 3 and are spring pressed by the springs 40. The cross bar 28 is held in position while the bushings are being forced over the arbors and the ends of the arbors are fitted into the recesses 26 formed in the ends of the punches. The latches 39 are then tripped by the levers 41. The levers 41 are pivoted on the bolts 42 that thread into the head 28 and are provided with cam surfaces 43 that operate upon rollers 44. The. ends Of the levers 41 are elastically held by the spring` pressed block 45 and are located so as to be moved downward against lthe block 45 by the end of the rod 46 which is secured to the ram 1. `When the cross head channels 56. are raised the portions 51 of the arbors arbors are held in position relative to the punches by the roller 37 which moves into the. channel 47' of' the cam 35 which operates to lift the rod 34. This movement is communicated to the cross head 28 through the levers 30 and 32 and the links 38.

The arbors 25 have portions that have differing diameters. The end portions 48 of the arbors are made so as to fit the bushings 277 preferably to tightly fit the bushings so as to firmly support the bushing walll The arbors also have the portions 49 which fit the cylindrical surfacesk of the rings 22. Thus the die coacts to hold the arbors in position. The. bushings 18 located` in the bolster plate are made relatively long and the portions 50 'of the arbors fit the bushings 18 which have diametersl greater than that of the portions 49 of the arbors and of the cylindrical surfaces of the rings 22. The portions 51 of the arbors are further increased in diameter and the lower ends of the arbors are provided with flanges 52 which are secured to the cross head 28 by suitable bolts. By this means the arbors are securely held in position and by the stepped relation of the portions of the arbors the stability of the arbors is greatly increased. and consequently the bushings are rigidly held in position in the die, particularly as against any sidewise movement of the bushings. This is, particularly, to prevent anyf irregularities in the finished product due to slight Variations in the metal of the bushings that might cause variation locally in the elasticity of the metal of the bushing.

In order to remove the bushings from the arbors after they have passed through the dies the arbors are carried down so as to draw the bushings through the sleeves 18 until the bushings are engaged with the stripper 53. The stripper 53 is supported and guided by the rods 54 having the heads or` shoulders 55 to limit the downward movement of the strip-per 53. The portions 49 and 50 of the arbors have channels 56 that extend into the said portions a depth equal to the respective differences ofthe radii of veach of said portions andthe portions 48 onto which the bushings are forced. rllhe stripper 53 is provided with prongs or fingers 58 that extend to the bottom ofthe When, therefore.v the arbors engage the prongs 58l and raise the strip-per along the rods 54. When. however, the arbors descend the stripper is carried down until it reaches the heads 58. Upon further Suitable'means may be provided for placing thebushings in position above the dies. In the machine shown the bushings 27 are placed in front of anvils 60 that are secured to the bolsterv plate 4. Two pairs of spring' arms 61 are secured to a bar 62 that is connected by means of a plate 63 and a bracket 64 to a reciprocable piston that is operated in the cylinder 65. The plate 63 is guided in its movements by rods 66 that extend` through depending brackets 67. The piston may be pneumatically operated, a. suitable means being provided for exhausting the lair and connecting a source of air pressure supply alternately from and toopposite ends of the cylinder. The cylinder is connected to a suitable two-way valve 68 by means of tubes 69. The valve 68 is operated by a sector 70 having pins 71 that. are operated upon by a cam bar 72 to throw the sector first to one position andthen to another position, and back again to thefirst position, and so on continuously synchronously with the movements of the ram 1, and so as to cause the fingers 61 to move towards the anvils 60 when the ends of the punches 5 are drawn within the centering bosse-s 9 of the cross bar 8 and immediately causing a return movement of the fingers 61.to draw the bushings rfrom theV anvils to points over the dies. In order to accomplish this synchronous movement as between the operations of the fingers 61 and thepunches 5 the cam bar 72 is connected by means of a rod 74 and a bracket 73` to the ram 1.

In order to cause engagement of the bushings by t-he fingers the ends of the fingers may be provided with clutch or engaging members 74 that have surface inclined to i;

the direction of the movements of the fingers 61 so Vas to cause the engaging members 74 to bespread. and also to cause the engaging member 74 to seize and hold the bushings in upright posit-ions as they are drawn "-f from theanvils to broaching positions, such as the surfaces 75 and the surfaces 76.

1. Ina bushing broaching machine, a

punch, a broaching die, a member having a cylindrical surface for securely holding the vbushing Yby engagement with one of the cylindrical' surfaces of the bushing, means for operating the punch to force the bushing.. into engaging relation with the member and subsequently to force the bushing .past the broaching die. and guide members for holding the said cylindrical surface of the bushing coaxial with the die.

2. In .a bushing broaching machine. a punch, a.. die, a member having a cylindricalsurface for securely holding the bush-A ing by engagement with one ofthe cylindrical surfaces of the bushing, a ram, the punch so connected to the ram as'A4 to perlUU of a bushing to be breached, and a sleeve surrounding the arbor and located directly below the die, the upper end of said arbor engaged and firmly held in the recess in the lower end of the punch, the lower end of the arbor being of a larger diameter than the upper end and having an accurate sliding it in the sleeve, thus` holding the arbor concentric and in perfect alignment with the cutting dies and the punch, means for operating the punch to force a bushing into engaging relation with the arbor and subsequently to force the bushing through the breaching die, while the punch, the bushing and the arbor are thus securely interlocked and guided.

17. In a bushing breaching machine, a punch having a recess in its lower end, a breaching die having cutting edge and cylindrical burnishing surface, an arbor fitting the inner cylindrical surface of a bushing to be breached, and a sleeve surrounding the arbor and located directly below the die, the upper end of said arbor engaged and iirmly held in the recess in the lower end of the punch, the lower end of the arbor being of a larger diameter than the upper end and having an accurate sliding iit in the sleeve and in the burnishing surface of the die, thus holding the arbor concentric and in perfect alignment with the cutting dies and the punch, means for operating the punch to force a bushing inte engaging relation with the arbor and subseqently te force the bushing through the breaching die, while the punch, the bushing and the arbor are. thus securely interlocked and guided.

18. In a breaching machine, a ram, a punch so connected tothe. ram as topermit tree lateral movement of the punch relative to the rain, and having-a recess, a bolster plate, a breaching die located in the bolster plate, an arbor extending through the die, means for raising the arbor to raise the bushing within the centering means of the punch, means for operating the punch to force the bushing over the arbor until the arbor engages the punch within the recess, and lowering the arbor to Jforce the bushing through the die while the arbor is held in the recess of the punch, the centering means of the punch being located at a distance above the die substantially equal to the length of the bushing.

19. In a bushing breaching machine,'a ram, a punch so connected to the ram as t-o permit free lateral movement of the punch relative to the ram, and having a recess, a bolster plate, a breaching die located in the bolster plate, an arbor extending through the die, means for raising the arbor to raise the bushing within the centering means of the punch, means for operating the punch to force the punch within the recess, and lowering the arbor until the arbor engages the punch within the recess, and lowering the arbor to force the bushing through the die while the arbor is held in the recess of the punch, the centering means of the punch being located at a distance above the die substantially equal to the length of the bushing, a stripper member located below the llie for stripping the bushing from the ar 20. In abushing breaching machine, a ram, a punch so connected to the ram as to permit free lateral movement of the punch relative te the ram, and having a recess, a bolster plate, a breaching die located in the bolster plate, an arbor extending through the die, means for raising the arbor to raise the bushing within the centering means of the punch, means for operatingthe punch to force the bushing over the arbor until the arbor engages the punch within the recess, and lowering the arbor to force the bushing through the die while the arbor is held in the recess of the punch, the centering means of the punch being located at a distance above the die substantially equal to the length of the bushing, a stripper member located below the die for stripping the bushing from the arbor, a feeding means for elastically engaging and positioning the bushings over the breaching die.

In testimony whereof, I have hereunto signed my name to this speciiication.

vAUGUSTUS F. DONALDSON. 

